immunogenicity study of antibody persistence and booster effect of pentaxim™ at 18 months in healthy argentinean infants

Conditions: Diphtheria; Tetanus; Pertussis; Poliomyelitis; Hepatitis B

Summary: this study will assess both the antibody persistence of the investigational vaccine and the immune response and safety of a booster dose of pentaxim™ vaccine in 18 months-old toddlers who participated in an earlier study in order to determine if they are still protected before they receive a booster dose of d, t, ipv, pertussis or hib vaccines and also to assess the quality of the induced immune memory in response to a booster dose of the same vaccine as in the primary series. primary objective: to describe the antibody persistence at 18 months of age and the booster effect of a dose of pentaxim™ on immunogenicity. secondary objective: to describe the safety profile of the booster dose pentaxim™ in each vaccine group defined by the vaccines received during the primary series.


Eligibility criteria:
inclusion criteria: * toddler at 18 months of age (range: 510 days to 578 days of age inclusive) * participated in study a3l02 (nct00831311) and has completed the three-dose primary series with either diphtheria, tetanus, pertussis (2-component acellular), recombinant hepatitis b hansenula and poliomyelitis vaccine adsorbed, and haemophilus influenzae type b vaccine, conjugated to tetanus protein (dtap-ipv-hb-prp\~t) or pentaxim™ and engerix b® pediatrico at 2, 4, and 6 months of age * written informed consent form signed by at least one parent or by a legal representative and an independent witness * able to attend all scheduled visits and to comply with all trial procedures. exclusion criteria: * participation in another clinical trial in the four weeks preceding the trial vaccination * planned participation in another clinical trial during the present trial period * congenital or acquired immunodeficiency, immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within the preceding 6 months or long-term systemic corticosteroids therapy * systemic hypersensitivity to any of the vaccine components or history of a life-threatening reaction to a vaccine containing the same substances * chronic illness at a stage that could interfere with trial conduct or completion * blood or blood-derived products received in the last six months * any vaccination in the four weeks preceding the trial * vaccination with a vaccine containing diphtheria, tetanus, pertussis, haemophilus influenzae type b, polio, or hepatitis b antigen, since the end of the primary series * history of documented diphtheria, tetanus, pertussis, haemophilus influenzae type b, polio, or hepatitis b infection(s) (confirmed either clinically, serologically, or microbiologically) * thrombocytopenia or bleeding disorder contraindicating intramuscular vaccination * history of seizures * fever (axillary temperature ≥37.4°c or equivalent rectal temperature ≥38.0°c) or acute illness on the day of inclusion * known contraindication to further vaccination with a pertussis vaccine such as: * encephalopathy; inconsolable crying for \>3 hours within 48 hours following vaccine injection * hypotonic hyporesponsive episode within 48 hours following vaccine injection * seizures with or without fever within three days following vaccine injection * axillary temperature \>39.4°c or equivalent rectal temperature \> 40.0°c within 48 hours following vaccine injection.

Keywords: diphtheria tetanus pertussis whooping cough haemophilus influenzae type b hepatitis b poliomyelitis